Cant Get Idle Low Enough

Foxybody95

Member
Sep 14, 2015
90
3
8
Hey guys me again, My car though its running great wont idle at less han 1100. It has an E cam with 1.7 rockers so i know its supposed to idle higher than a stock vehicle but this is too high. I follow the correct idle learn procedure get the thing to idle at 850 and it idles perfectly but the moment I plug the Iac back in its back up to 1100 again. The I tried backing off the idle with the iac plugged in and it sort of works but it surges a little bit but once I shut the car off and turn it back on its right back up to 1100 again only this time it surges and wants to keep dying. Any ideas?
 
You guys with idle/stall problems could save a lot of time chasing your tails if you would go through the Surging Idle Checklist. Over 50 different people contributed information to it. The first two posts have all the fixes, and steps through the how to find and fix your idle problems without spending a lot of time and money. It includes how to dump the computer codes quickly and simply as one of the first steps. I continue to update it as more people post fixes or ask questions. You can post questions to that sticky and have your name and idle problem recognized. The guys with original problems and fixes get their posts added to the main fix. :D

It's free, I don't get anything for the use of it except knowing I helped a fellow Mustang enthusiast with his car. At last check, it had more than 250,000 hits, which indicates it does help fix idle problems quickly and inexpensively.
 
Oh trust me I know about it. i've used it countless times and I thank you very much for putting it up there. But his isnt a surge its a high idle and the only code the computer dumps is the code 11 for system okay.
 
Unplug the IAC completely. Then unscrew the idle stop screw to drop idle down.

Then, unplug the battery for 30 mins. Plug the IAC back in. Hook battery up, start engine.

Let idle 2 min no accessories. Then 2 min with everything you can possibly put on turned on.
 
Unplug the IAC completely. Then unscrew the idle stop screw to drop idle down.

Then, unplug the battery for 30 mins. Plug the IAC back in. Hook battery up, start engine.

Let idle 2 min no accessories. Then 2 min with everything you can possibly put on turned on.

If this doesn't work, start looking for a vacuum leak. I had a cap on a vacuum line under the upper intake manifold deteriorate to the point that it was worthless. Look at it with the upper intake manifold in place and you couldn't tell that there was anything wrong with it